Significant advancements in the development of robots and robotic devices have been achieved in recent decades. Manufacturing efficiencies gained through the use of robotic assemblers and manipulators, exploratory robotic vehicles (such as those traveling the surface of Mars), and animatronics characters often seen at theme parks and other sights of attraction are but a few popular examples. Each of these specialized robots have common characteristics, however, in that they do not have true human-like capabilities, nor do they function with human-like operation. Indeed, many robotic devices are tethered to external power sources, while others are configured to move without bi-pedal or human-like locomotion. True mobile and un-tethered human-like robots and exoskeletons, while in existence, are in the early stages of development, and are continually being improved to better participate in mobile, human-like activities.
One reason for the continuing technological difficulty in advancement of human-like, or biomimetic, robotic systems toward un-tethered human-like robotic activity is the inefficiency inherent within the mechanical joints that provide the robots with the ability to move. In a robotic device, movement about a mechanical joint is a primary consumer of power. Yet with few exceptions the mechanical joints in robots and human assistance devices have been optimized for control and performance, these taking precedence over optimal efficiency considerations. For instance, many modern non-biomimetic industrial robots perform significant work with the advantage of being permanently connected to external electrical, fluid or mechanical power systems that can supply a surplus of power, leading to articulating joints capable of precise and powerful movements, but which are also highly wasteful of energy.
Efficiency has also suffered in powered prosthetic limbs as these devices have been primarily confined to the laboratory, research centers, or individuals living in populated areas with ready access to sources of power. In a remote work or battlefield environment, however, efficiency is critical for long-term operation and/or survivability, as an exoskeleton or human-like robot is useless if it prematurely runs out of fuel or discharges its batteries. Advancements in more efficient operation of human-like robotic devices or exoskeletons, particularly more efficient operation of the biomimetic joints through a range of movements and load conditions, without sacrificing speed or power, are greatly needed and will serve to provide improved, un-tethered human-like robotic activity.